Chair control



3 Sheets-Sheet 1 J. R. MEINHARDT CHAIR CONTROL IME Sept. 7, 1965 FiledApril 20, 1964 Jbzzzes f%ez zardi Sept. 7, 19 65 J. R. MEINHARDT CHAIRCONTROL 3 Sheets-Sheet 2 Filed April 20, 1964 Sept? 19-65 J; R.MEINHARDT 3,204,914

CHAIR CONTROL Filed April 20, 1964 3 SheetsSheet 3 United States Patent3,204,914 CHAIR CONTROL James R. Meinhardt, Park Ridge, 111., assignorto The Selig Company, a corporation of Illinois Filed Apr. 20, 1964,Ser. No. 360,906 Claims. (Cl. 248374) This invention relates to a chaircontrol, or chair iron, and more particularly to an office chair controlsuch as nlilight be used in a swivelchair or a stenographic posture can.

A primary object of the present invention is to provide a new andimproved chair iron of simplified construc-' tion in which a tiltableseat or back rest is pivotally mounted upon a headpiece and urged towarda normal position by a rubber torsion member which is generally of thetype disclosed in Herold Patent No. 2,087,254.

It is desirable in chair irons to provide some means for adjusting thespring tension which resists the tilting movement of the seat or back sothat the chair may comfortably accommodate persons of different Weight.In prior devices, the'headpiece and spring adjusting mechanism werecomplex and made from relatively heavy materials; while in the presentinvention the headpiece and spring adjusting mechanism require only afew commercially available parts and members which are readilyfabricated by stamping.

A more specific object of this invention is to provide a chair ironheadpiece which is made from a generally U-shaped plate. By constructingthe headpiece in this manner, several functional advantages areprovided. The rubber torsion member, the torsion adjusting mechanism,the movement limiting stops, and the support post may all be enclosedwithin the U-shaped headpiece, thereby providing a very compact andstrong structure.

A further object of the present invention is to provide a chair iron inwhich the arms of a U-shaped headpiece serve both to rigidly fasten theheadpiece to the support post and to limit the pivotal or tiltingmovement of the seat or back in both directions. By providing aprojection on the tilting seat fixture and extending it between the armsof the U-shaped headpiece, a very effective and simple limit stopresults.

Another object of the present invention is to provide a chair iron inwhich a rubber torsion device has inner and outer metal sleeves with arubber sleeve bonded between them, the inner sleeve is detachablyconnected to the tilting seat or back support, and an adjusting meansincluding a screw threaded in the headpiece controls the prestress ofthe rubber sleeve by bearing upon a shoulder on the outer sleeve.

Another and more specific object of the present invention is to providea chair iron which has a fixed support post and a seat fixture tiltablerelative to the support post, a U-shaped headpiece having arm portionsattached to the support post, a rubber torsion device seated within thebight of the headpiece, an elongated channel member extending from achair seat or back fixture support between the headpiece arm portionsadjacent the support post with upper and lower stops adapted to contactthe headpiece arm portions when the seat is tilted in either direction,an L-shaped plate having two legs slidable on one of the headpiece armsand in engagement with an outer metal' sleeve of the rubber torsiondevice, and a screw threaded in the headpiece for adjusting the L shapedplate to vary the prestress in the torsion device.

A preferred embodiment of the invention is illustrated in theaccompanying drawings as applied to both an oflice swivel chair and to astenographic posture chair, and in the drawings:

FIGURE 1 is a fragmentary, side elevation of a stemgraphic posture chairincorporating the present invention;

FIGURE 2 is a plan view of the torsion spring adjusting plate;

FIGURE 3 is a side elevational view of the torsion spring;

FIGURE 4 is a fragmentary, side elevational view, partially in section,of the device of FIGURE 1 with the back rest in a tilted position;

FIGURE 5 is a fragmentary sectional view, taken generally along line 55of FIGURE 1, showing the headpiece and fixture support;

FIGURE 6 is a fragmentary sectional view, taken generally along line 66of FIGURE 5, showing the abutment surfaces on the outer sleeve of thetorsion spring which receive the adjusting plate;

FIGURE 7 is a fragmentary, side elevational view of an office swivelchair incorporating the present invention with the seat in normalposition; and

FIGURE 8 is a fragmentary, side elevational view, partly in section, ofthe device of FIGURE 7 with the seat tilted.

Referring to FIGURES 1 and 4, a post provides a vertically adjustableportion of a base, indicated generally at 10, and has a reduced upperend portion 11 and a further reduced extremity 12 forming shoulders 13and 14 that support a U-shaped headpiece, indicated generally at 15. Theheadpiece has a lower arm 16 impaled by the post portion 11 and restingon the shoulder 13, a rear bight portion 17, and an upper arm 18 impaledby the post extremity 12 and resting on the shoulder 14. A fixed seatbracket 19 has a cross web 20 seated on the arm 18, impaled by the postextremity 12, and is fixed to the headpiece by a head 21 on the post. Atthe front of the lower headpiece arm 16 is an upright flange 22 having athreaded hole 23. i

A torsion unit or resilient unit 24 is mounted in the bight 17 of theheadpiece and includes an inner rotatable metal sleeve 25, an outernormally stationary metal sleeve 26, and an intermediate rubber sleeve27 which is bonded to both the metal sleeve. As best seen in FIGURE 3,the inner sleeve has aligned grooves 28 at both ends; and as best seenin FIGURE 6, the outer sleeve 26 has slots 29 forming forwardly facingshoulders 30. A bolt 31 extending through the inner sleeve 25 provides apivot for the torsion unit and for a fixture support, indicatedgenerally at 32.

Referring to FIGURES 4 and 5, the fixture support 32 consists of aU-shaped pivot member 35 and a bracket 36 having leg portions 37 and 38flanking the U-shaped member 35 and pivotally connected thereto by pivotpins 40 and 41 A threaded draw row assembly, generally indicated by thenumeral 44, clamps the bracket 36 to the U-shaped member 35 in thedesired angular position.-

The U-shaped pivot member 35 has stepped legs 45 and 46 which flank theheadpiece 15 and have apertured internal bosses 48 and 49, respectivelywhich receive the bolt 31'and engage the grooves 28 on the ends of theinner sleeve 25 of the torsion unit thereby providing a pivotal mountingfor the fixture support 32 on' the head- A conventional back restassembly 39 is vertically slidable on the bracket 36 to which it issecured in anadjusted position byf'a hand screw 42; A hand wheel 73 onthe draw boltassembly 44 permits the back rest assembly- 12 and thebracket 36 to be locked in any desired angular Patented Sept. 7, 1965position relative to the fixture support 35. The fixture support 32, theback rest assembly 39 and the inner sleeve rotate as a unit within theheadpiece 15.

Referring now to FIGURES 4 and 5, a forwardly open channel memberconnects the forward parts of the legs 45 and 46 of the U-shaped member35. A lower web 51 of the channel provides a stop having rubber pads 52and 53, and an upper web 55 provides a stop having rubber pads 56 and57, said stops 51 and 55 abutting, respectively, against the lower arm16 and the upper arm 18 of the headpiece to limit pivotal movement ofsaid fixture support in both directions.

The prestress of the torsion unit 15 is adjustable by an assembly thatconsists of an L shaped bifurcated adjusting late 60 slidably mounted onthe lower arm 16 of the headpiece 15, and a screw 61 threaded throughthe hole 23 in the headpiece flange 22 and cooperating with saidadjusting plate. As shown more clearly in FIGURE 2, the adjusting platehas legs 62 and 63 which flank the post 11 and have engaging surfaces 64and 65 that abut the shoulders 30 of the torsion unit outer sleeve 26,and an upstanding web 66 at the front of the plate with an aperture 67which receives a stepped end of the adjusting screw 61. Thus, rotationof the adjusting screw to move the plate to the left in FIGURE 1, servesto turn the outer sleeve 26 clockwise and increase the prestress in therubber sleeve 27.

Referring to FIGURES 7 and 8 wherein the chair iron is shown with atiltable seat fixture rather than the tailtable back rest assembly ofFIGURES 1 to 6, a post provides a vertically adjustable portion of abase, indicated generally at 110, and has a reduced upper end portion111 affording shoulders 113 and 114 that support a U- shaped headpiece115 held on by a head 121 on the post.

Headpiece 115 is identical with headpiece 15 and is thus not describedin detail; and a torsion unit 124 is identical with unit 24 and thusalso not described in .detail except to statethat it includes an innersleeve 125 having grooves 128 at its ends. A seat and back rest 176 areresiliently tiltable as a unit about the headpiece 115. A seat fixturesupport 177 has vertically depending legs 178 and 179 which flank theheadpiece 115 and have inwardly extending bosses 180 stamped thereinwhich engage the grooves 128 in the ends of the inner sleeve 125 therebyfixing the seat fixture support 179 to the inner sleeve. A bolt 181impales the depending legs 178 and 179 thereby permitting the seatfixture support 177 to tilt in a counterclockwise direction While thetorsion unit urges the fixture support in a clockwise direction. Achannel member 183 connects the forward portions of the depending plates178 and 179 providing limit stops 184 and 185 in the same manner as thestops 51 and .55 in the device of FIGURES 1 to 6. The adjusting plate187 is constructed and operates in the same manner as the adjustingplate 60, as described with respect to FIGURES 1 to 6.

The foregoing detailed description is given for clearness ofunderstanding only and no unnecessary limitations are to be understoodtherefrom, as some modifications will be obvious to those skilled in theart.

I claim:

1. A chair iron comprising: a base; a headpiece on said base; aresilient unit mounted on said headpiece having one portion thereofnormally stationary with respect to said headpiece and having a secondportion thereof rotatable with respect to said headpiece; a fixturesupport connected to said second portion for tilting movement relativeto the base, and biased to a predetermined position by the resilientunit; and an adjusting plate slidably mounted on said headpiece forrectilinear movement and engaging said one portion of said resilientunit whereby the resistance to tilting of the fixture support may beadjusted.

2. A chair iron, comprising: a base; a headpiece mounted on said baseand having vertically spaced arm portions; a resilient torsion unitmounted on said headpiece between said arm portions, said unit includingan outer sleeve normally stationary with respect to said headpiece, aninner sleeve, and a resilient member interposed between and secured tosaid outer and inner sleeves; a fixture support connected to said innersleeve for tilting movement relative to said base and biased to apredetermined position by said torsion unit; an adjusting plate slidablymounted on one of said arm portions for rec-tilinear movement andengaging said outer sleeve; and means mounted on said one arm portionand engaging said plate to slide the latter and rotate the outer sleeve,whereby the torsional resistance to movement of said fixture support maybe varied by changing the prestress of the resilient member.

3. A chair iron, comprising: a base; a generally U- shaped headpiecemounted on said base and having two vertically spaced arm portions; aresilient unit mounted in said headpiece, said resilient unit having oneportion thereof normally stationary with respect to said headpiece and asecond portion thereof resiliently movable with respect to saidheadpiece; a fixture support connected to said second portion fortilting movement relative to said base; and a projection on said fixturesupport extending between said arm portions, said projection havingmeans for engaging each of said arm portions at either extreme positionof the tiltable fixture support whereby the tilting movement of thefixture support is limited.

4. A chair iron, comprising: a base including an upright. post; agenerally U-shaped headpiece having vertically spaced arm portions, bothof which are impaled by said post, one arm of said headpiece having anupright flange opposite the bight of the U; a resilient unit includingan outer sleeve mounted in said headpiece and having an abutment surfacethereon, an inner sleeve, and a resilient sleeve interposed between andbonded to said outer and inner sleeves; a fixture support connected tosaid inner sleeve for tilting movement relative to said headpiece andbiased to a predetermined position by said resilient unit; an elongatedprojection extending from said fixture support between said headpiecearm portions, said projection having upper and lower stops thereon forengaging said headpiece arm portions to limit movement of said fixturesupport; an L-shaped plate having two legs, one of said plate legs beingbifurcated and slidably mounted on one of said headpiece arm portionswith its bifurcated legs flanking said post and engaging said abutmentsurface; and a screw threadedly engaging the flange on said headpieceand abutting said other plate leg, whereby the torsional resistance tomovement of said fixture support may be varied by turning said screw toslide the plate and thus change the prestress of the resilient sleeve.5. A chair iron, comprising: a base including an upright post; agenerally U-shaped headpiece having two vertically spaced arm portionsimpaled by said post; a torsion unit mounted in the bight of saidV-shaped headpiece; said torsion unit including an outer sleeve, aninner sleeve having grooves at each end, and a resilient sleeveinterposed between said outer and inner sleeves; means on said headpiecefor normally retaining said torsion unit in a fixed position in thebight of said U; a fixture support having arms flanking said headpiece,each of said arms having an internal boss fitted within one of saidgrooves, whereby said fixture support is tiltable relative to said baseand biased to a predetermined position by said torsion unit.

6. The chair iron of claim 5, and further including, a projection onsaid fixture support extending between said arm portions, saidprojection having means for engaging each of said arm portions at eitherextreme position of the tiltable fixture support, whereby the tiltingmovement of the fixture support is limited.

7. The chair iron of claim 5, and further including, means on saidheadpiece for engaging and rotating said outer sleeve relative to saidheadpiece whereby the prestress of the torsion unit may be adjusted.

8. A chair iron, comprising: a base; a generally U- shaped headpiecemounted on said base and having two vertically spaced arm portions; atorsion unit mounted within the bight of said U-shaped headpieceincluding, an outer sleeve having a slot therein forming an abutmentsurface, an inner sleeve, and a resilient sleeve interposed between saidouter and inner sleeves; adjusting means on said headpiece and engagingsaid abutment surface for changing the prestress of the torsion unit;and a fixture support connected to said inner sleeve for tiltingmovement relative to said base and biased to a predetermined position bythe torsion unit.

5 between the fixture support and the inner sleeve comprisesinterengaging bosses and slots.

References Cited by the Examiner UNITED STATES PATENTS 7/37 Herold248374 3,120,942 2/64 Sauage 248-374 CLAUDE A. LE ROY, Primary Examiner.

1. A CHAIR IRON COMPRISING: A BASE; A HEADPIECE ON SAID BASE; ARESILIENT UNIT MOUNTED ON SAID HEADPIECE HAVING ONE PORTION THEREOFNORMALLY STATIONARY WITH RESPECT TO SAID HEADPIECE AND HAVING A SECONDPORTION THEREOF ROTATABLE WITH RESPECT TO SAID HEADPIECE; A FIXTURESUPPORT CONNECTED TO SAID SECOND PORTION FOR TILTING MOVEMENT RELATIVETO THE BASE, AND BIASED TO A PREDETERMINED POSITION BY THE RESILIENTUNIT; AND AN ADJUSTING PLATE SLIDABLY